> From: david_gonda at quickmail.cis.yale.edu (David Gonda)
> To: "bionet.microbiology mail newsgroup" <bionet-news at dl.ac.uk>
> Subject: Effects of magnetic fields on bacterial growth?
>> Does anyone know of any evidence, either peer reviewed or anecdo-
> tal, regarding the effect of magnetic fields on bacterial growth?
> Thanks...
> David Gonda, Yale University, Dept of Molecular Biophysics and
> Biochemistry <david_gonda at qm.yale.edu>
> [the opinions above, which are mine, are only mine, and belong to
> me]
1. The magnetic effects on bacterial growth are known. But it does
not mean that it has already been studied. The main investigations of
the field developed in two directions.
1.1. The first one is study on magnet-sensetive components in cells.
The publications mostly connected with description of magnetosomes
[1,2], but it was also a review by Verkhovtseva [3,4] on measurement
of tiny magnetic effect on iron-containing compounds in many diffe-
rent kinds of bacteria. By the way, she has suggested that bacteria
can use the magnetic energy for their flagella movement...
1.2. The second direction of investigations is study of combined
influence of electric and magnetic fields on activity of enzymes
[5,6]. Never think that electric field is too artificial phenomenon
for bacteria. During reduction of media with metallic iron/steel
(exx: bionet.microbiology Msg # 1976 of 14 Apr 95 from Steve Zinder,
"Re: Methanogens and hydrogen"), attached cells are at zone with
gradient of potentials equal 0.2 V. During migration of magnetic
bacteria into sediment, they changed zone with Eh=+ 50 mV to anaero-
bic zone with Eh=-200 mV, i.e. it is movement inside of gradient
equal 0.25 V. I syggest that in nature magnetotactic bacteria migrate
not to the magnet pole of Earth but to accumulated pyrite in deep
layers of sediments [7].
2. In 1993 I've isolated original magnetotactic bacterium (not pub-
lished yet) from a sample kindly presented me by E.Matitashvili [8].
Last year I've transformated a half of dozen type (referent) strains
belonging to different species and genera into magnetotactic forms.
I've got the result by modification of the medium and culture condi-
tions. The strains belong to two systematic groups of bacteria. The
short paper with descriptions of the magnetotactic bacteria is in
preparing. A couple of strains showed a change of structure of bio-
mass flocks in liquid medium on days of stong geomagnetic storms.
3. Reason for answering through the Net.
Recently we have problems with research investigations. I waste
weeks and months to get a good electron microscopy or analysis of
intracellular inclusions. If you are interested with the topic and
can provide financial support or our cooperation in some Grant
Programm,- you are welcomed for collaboration.
1. Stolz J.F.- Magnetosomes. J.gen.Microbiol., 1993, v.139, pp.1663
-1670.
2. Kawaguchi R., Burgess J.G., Sakaguchi T., Takeyama H., Thornhill
R.H., Matsunaga T.- Phylogenetic analysis of a novel sulfate-
reducing magnetic bacterium, RS-1, demonstrates its membership
of the s-Proteobacteria. FEMS Microbiol.Lett, 1995, v.126, pp.
277-282.
3. Verhovtseva N.A.- Formation of magnetite by bacteria, and magne-
totaxis. (in russian) In: Uspehi Mikrobiologii, 1992, v.25, pp.
51-79.
4. Verhovtseva N.A.- Transformation of iron compounds by hetero-
trophic bacteria. (in russian) Sc.D.Thesis, Moscow, Moscow State
University, 1993.
5. Novikov V.V., Zhadin M.N.- Combined Action of Weak Static and
Alternating Low Frequency Magnetic Fields on Ionic Currents in
Aqueous Amino Acid Solutions. Biofizika, 1994, v.39, pp.45-49.
6. Patent USA 5350686 (94.09.27)
7. Winestein (Vainshtein) M.B., Namsaraev B.B., Samarkin V.A., Lein
A.Yu.- Modern processes of sulfate reduction in Indian ocean
sediments. (in russian) In: "Geochemistry of diagenesis of the
Indian ocean sediments" (eds.Volkov I.I., Rosanov A.G.): 45-52.
Moscow, Inst.Oceanology, USSR Acad.Sci., 1985.
8. Matitashvili E.A., Matojan D.A., Gendler T.S., Kurzchala T.V.,
Adamia R.S.- Magnetotactic bacteria from freshwater lakes in
Georgia. J.Basic Microbiol., 1992, v.32, pp.185-192.
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Mikhail Vainshtein (in publications translated from russian also:
Vainstein, Vaynshteyn, Winestein)
Curator of bacteria of All-Russian Collection of Microorganisms
(VKM), IBPhM, Russ.Acad.Sci., Pushchino; Assistant Professor,
Pushchino State University. E-mail: vain at ibpm, serpukhov, su